Drug Delivery And Diagnostic System For Orthopedic Implants

ABSTRACT

A drug delivery and diagnostic system can include an orthopedic implant having an outer attachment surface. A conduit can be coupled to the outer attachment surface. The conduit can have an inlet and a plurality of perforations formed along a length thereof. The conduit can be adapted to pass fluid between the inlet and the perforations. A subcutaneous port can be fluidly coupled to the inlet and be adapted to communicate fluid through the inlet, along the conduit and out of the perforations around and along the outer attachment surface of the orthopedic implant.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/039,362 filed Mar. 3, 2011, which claims the benefit of U.S.Provisional Application No. 61/311,096 filed Mar. 5, 2010. The entiredisclosures of the above applications are incorporated herein byreference.

FIELD

The present disclosure relates generally to orthopedic implants and morespecifically to orthopedic implants having a drug delivery anddiagnostic system.

BACKGROUND

This section provides background information related to the presentdisclosure which is not necessarily prior art.

Orthopedic implants have been used to partially or entirely replacebones and joints that may be damaged. In some examples however,infection on or near such orthopedic implants may take place afterimplantation of the orthopedic prosthesis. Moreover, the onset ofinfection on or near the orthopedic implant and tissue interface may bedifficult to detect. Furthermore, the type of infecting agent may alsobe unknown. In some examples, once an infection is eventually detected,the recourse may be invasive and include extraction of the orthopedicimplant and subsequent revision surgery. To address such concerns drugcoated orthopedic implants have been developed. Drug coated orthopedicimplants provide a coating on the implant to be effective againstvarious bacteria and strain. Drug coated implants are generally mosteffective immediately after implantation of the orthopedic implant, suchas when the eluting mechanism is activated upon contact with bodilyfluid.

SUMMARY

This section provides a general summary of the disclosure, and is not acomprehensive disclosure of its full scope or all of its features.

A drug delivery and diagnostic system can include an orthopedic implanthaving an outer attachment surface. A conduit can be coupled to theouter attachment surface. The conduit can have an inlet and a pluralityof perforations formed along a length thereof. The conduit can beadapted to pass fluid between the inlet and the perforations. Asubcutaneous port can be fluidly coupled to the inlet and be adapted tocommunicate fluid through the inlet, along the conduit and out of theperforations around and along the outer attachment surface of theorthopedic implant.

According to additional features, the conduit can be spirally wrappedaround the outer attachment surface. The conduit can be formed ofbiocompatible metal or polymer. The conduit can be attached to the outerattachment surface, such as by welding, brazing or gluing.

According to other features, a drug delivery system can comprise anorthopedic implant having a blind bore formed thereon and at least onepassage that fluidly connects the blind bore with an outer surface ofthe orthopedic implant. An implant module can have a reservoir, a firstradio frequency (RF) receiver, a fluid reservoir, and a valve that isselectively movable from a closed position wherein fluid is retained inthe reservoir and an open position wherein the fluid is communicated outof the reservoir. The implant module can have an insertion end that isadapted to couple to the orthopedic implant at the blind bore. Ahandheld device having a second RF transmitter can communicate with thefirst RF receiver. The handheld device can be operable to send a signalfrom the second RF transmitter. The first RF receiver is operable toinitiate movement of the valve to the open position upon receipt of thesignal from the second RF transmitter.

Further areas of applicability will become apparent from the descriptionprovided herein. The description and specific examples in this summaryare intended for purposes of illustration only and are not intended tolimit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIG. 1 is a perspective posterior view of a femoral stem implanted in anintramedullary canal of a right femur, the femoral stem incorporatingthe drug delivery and diagnostic system of the present teachings;

FIG. 2 is an exploded perspective view of the drug delivery anddiagnostic system of FIG. 1;

FIG. 3 is a perspective view of a drug delivery and diagnostic systemaccording to additional features of the present teachings;

FIG. 4 is a sectional view of the drug delivery and diagnostic systemtaken along lines 4-4 of FIG. 1 and shown prior to insertion of a needleinto a subcutaneous port implanted below the skin of a patient;

FIG. 5 is a cross-sectional view of the drug delivery and diagnosticsystem of FIG. 4 and shown subsequent to delivery of fluid throughrespective passages formed in the femoral stem;

FIG. 6 is an exploded view of a drug delivery system constructed inaccordance to additional features of the present disclosure andincluding a remote handheld device;

FIG. 7 is a perspective view of an acetabular cup incorporating a drugdelivery and diagnostic system according to additional features of thepresent teachings; and

FIG. 8 is a perspective view of a tibial tray incorporating a drugdelivery and diagnostic system according to other features of thepresent disclosure.

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference tothe accompanying drawings. While a femoral stem is shown in FIGS. 1-6,other implants such as acetabular cups (FIG. 7), tibial trays (FIG. 8)and others may be used in conjunction with the disclosed system.

With initial reference to FIGS. 1 and 2, a drug delivery and diagnosticsystem constructed in accordance to one example of the present teachingsis shown and generally identified at reference numeral 10. The drugdelivery and diagnostic system 10 can generally include an orthopedicimplant 12, a subcutaneous port 14, a flexible catheter 16 and anadapter 18. As illustrated, the orthopedic implant is in the form of afemoral stem 20. As will be described in greater detail herein, asyringe 22 having a plunger 24 and a needle 26 can be used with thesubcutaneous port 14, the flexible catheter 16 and the adapter 18 in afirst sequence to assist in diagnosing an infection that may be presentin the surrounding tissue adjacent the orthopedic implant 12. Thesyringe 22, plunger 24 and needle 26 can also be used with thesubcutaneous port 14, the catheter 16 and adapter 18 in a secondsequence to deliver drugs, such as antibiotics, cellular therapyincluding stem cells, such as from fat or bone marrow aspirate,autologous blood components or other flowable therapies to thesurrounding tissue adjacent the orthopedic implant 12.

As shown in FIG. 1, the femoral stem 20 is shown implanted into anintramedullary canal 28 of a femur 30. As best shown in FIG. 2, thefemoral stem 20 can generally comprise a body 32 having a proximal bodyportion 34 and a distal stem portion 36. A blind bore or inserter hole38 can be formed on the proximal body portion 34. The inserter hole 38can be tapered and have threads 40 formed around an inner diameterthereof. The inserter hole 38 can be used for coupling with an insertertool (not shown) during insertion of the femoral stem 20 into theintramedullary canal of the femur 30. The femoral stem 20 can furtherinclude a fluid passage system 40 that can include a primary passage 42that is fluidly coupled to the inserter hole 38 and to a series ofsecondary passages 44 defined within the implant 12. The secondarypassages 44 can extend to an outer surface 46 of the femoral stem 20. Byway of example, six secondary passages 44 are illustrated in theexemplary configuration of FIG. 1. However, it will be appreciated thatadditional or fewer secondary passages can be provided in the femoralstem 20 that fluidly connects the primary passage 42 with the outersurface 46. Furthermore, it will be appreciated that the secondarypassages 44 can be formed at right angles or non-orthogonal angles withrespect to the primary passage 42 and a long axis of the femur 30. Theproximal body portion 34 can further comprise a neck 50 having a maletaper 52. While not specifically shown, the male taper 52 can beoperable to couple with a femoral head as is known in the art. Theadapter 18 can generally comprise an adapter body 54 having alongitudinal tapered insertion end 56 that has adapter threads 58 formedaround an outer surface. An adapter nipple 60 can extend on an oppositeend of the adapter body 54. The adapter nipple 60 can include a rib 62thereon.

The subcutaneous port 14 can generally comprise a port body 64 that hasan artificial septum 66 arranged thereon. A subcutaneous port nipple 68can extend from the body 64. A rib 70 can be formed around thesubcutaneous port nipple 68. It will be appreciated that thesubcutaneous port 14 can take other forms. The catheter 16 can beoperable to be slidably advanced at opposite terminal ends onto theadapter nipple 60 and the subcutaneous port nipple 68, respectively. Thecatheter 16 can be coated with and/or made with antifouling(antibacterial) material.

In one example of assembling the adapter 18 to the femoral stem 20, theadapter threads 58 can be threadably advanced into the inserter hole 38at the proximal body portion 34 of the femoral stem 20. In this regard,the adapter threads 58 threadably advance around the threads 40 providedin the inserter hole 38. Again, the ends of the catheter 16 can beslidably advanced into a secure relationship with the respective adapternipple 60 and subcutaneous port nipple 68. It will be appreciated thatthe catheter 16 can comprise any length suitable for a particularpatient that allows the subcutaneous port 14 to be implanted under skin74 (FIGS. 1 and 4) at a convenient access area of the patient.

Turning now to FIG. 3, a drug delivery and diagnostic system 110constructed in accordance to additional features of the presentteachings is shown. In general, the drug delivery and diagnostic system110 can include a flexible pipe or conduit 112 that is wrapped around agroove 121 formed in an outer attachment surface 114 of a femoral stem120. It is appreciated that the groove 121 may extend further superiorlyup the neck of the femoral stem 120. The groove 121 can have a depthsuch that the conduit 112 does not extend past the outer attachmentsurface. The conduit 112 can generally comprise a plurality ofperforations 122 along its length. In other examples, the conduit 112can include one or a series of linear or substantially linear pipes thatbranch out and extend along the outer attachment surface 114. In oneexample, the conduit 112 can be formed of biocompatible metallicmaterial and can be attached to the outer attachment surface 114 (ormore specifically into the groove 121), such as by a welding or brazingtechnique. The conduit can alternatively be formed of a polymer andattached to the groove 121 by an adhesive such as glue. The drugdelivery and diagnostic system 110 can cooperate with the subcutaneousport 14 and the syringe 12 to deliver therapy and/or extract bodilyfluid during a diagnostic test as discussed with respect to the drugdelivery and diagnostic system 10 herein.

With reference now to FIGS. 4 and 5, a first method of using the drugdelivery and diagnostic system 10 will be described. In the first methodaccording to the present teachings, the drug delivery and diagnosticsystem 10 will be used to diagnose potential bacteria that may bepresent at an interface between the femoral stem 20 and the femur 30. Atthe outset, the surgeon can draw fluid from a container (not shown),such as saline into the syringe 22. Next, the surgeon can pierce theskin 74 of the patient and pierce the artificial septum 66 of thesubcutaneous port 14. The plunger 24 can then be depressed, such thatthe saline communicates through the catheter 16 and through the adapter18, through the primary and secondary passages 42 and 44 and ultimatelyinto the surrounding tissue around the outer surface 46 of the femoralstem 20. At this point, the saline can act to dislodge bacteria andtherefore mix with any potential bacteria. Next, a surgeon can retractthe plunger 24 and aspirate the saline and the bodily fluid thatsurrounds the outer surface 46. The resultant mixture can then becultured to determine if any bacteria (and specific type etc.) ispresent in the suspected infection site around the outer surface 46 ofthe femoral stem 20.

With specific reference now to FIG. 5, the drug delivery and diagnosticsystem 10 will be described in accordance to a second method where thesyringe 22 can be used to deliver a therapy, such as drugs, cellulartherapy and/or autologous blood components to the implant-tissueinterface. Again, it will be appreciated that with the first or secondmethod, the drug delivery and diagnostic system can be used at any time,such as immediately after implantation of the femoral stem 20 or at anytime, such as a year or many years after implantation of the femoralstem 20. Once the surgeon has determined what flowable agent is desiredto be communicated to the interface of the femoral stem 20 and femur 30,the surgeon can pierce the artificial septum 66 of the subcutaneous port14 with the needle 26 and depress the plunger 24 to deliver the flowableagent through the catheter 16, through the adapter 18 and through therespective primary and secondary passages 42 and 44. This enables thedrug to be delivered around a perimeter of implant 12 at the infectionsite. The system can therefore be more efficient and effective comparedto medications taken orally or intravenously.

With specific reference now to FIG. 6, a drug delivery system 210constructed in accordance to additional features of the presentteachings is shown. The drug delivery system 210 can generally includean orthopedic implant 212, an implant module 214 and a handheld device216. Unless otherwise described herein, the orthopedic prosthesis 212can be constructed similarly to the femoral stem 20 described in detailabove. In general, the drug delivery system 210 is operable to remotelycommunicate with the implant module 214, such that flowable material,such as antibiotics housed in the implant module 214 can be delivered tothe tissue interface between the orthopedic prosthesis 212 and the femur220.

The implant module 214 can generally comprise an insertion end 222having module threads 224. As with the adapter 18 described above, themodule threads 224 can be configured to threadably mate with blind borethreads 226 provided on an inserter hole 230 of the orthopedic implant212. The implant module 214 can further comprise a reservoir 232, avalve 234, an actuator 236 and a first radio frequency (RF) receiver238. The handheld device 216 can generally comprise a housing 240 havinga display 242, an interface panel 244 and a second RF transmitter 248.

One exemplary method of using the drug delivery system 210 will now bedescribed. Once a surgeon, medical professional or patient hasdetermined that antibiotics (or other flowable material describedherein) is desired to be communicated to a tissue interface between theorthopedic prosthesis 212 and the femur 220, a signal can becommunicated from the second RF transmitter 248 of the handheld device216. Upon receipt of the signal sent from the second RF transmitter 248,the first RF receiver 238 can communicate with the actuator 236 to causethe actuator 236 to open the valve 234 from a closed position to an openposition wherein antibiotics (or other fluid) can be communicatedthrough the primary passage 256 and secondary passages 258 and to thetissue interface between the orthopedic prosthesis 212 and the femur220.

Turning now to FIG. 7, an orthopedic implant 312 that incorporatesrespective passages 314 is shown. As illustrated, the orthopedicprosthesis 312 is in the form of an acetabular cup 320. The orthopedicprosthesis 312 can be used with other components described herein, suchas the subcutaneous port 14, the catheter 16 and the syringe 22. As canbe appreciated, the acetabular cup 320 can be used in a similar fashionas the femoral stem 20 described above. In this way, the fluid passages314 can be used to assist in diagnosing a potential infection and/or todeliver antibiotic or other flowable material to an outer surface of theacetabular cup 320.

As shown in FIG. 8, an orthopedic prosthesis 330 is shown thatincorporates fluid passage 332. The orthopedic prosthesis 330 is in theform of a tibial tray 334. As can be appreciated, the orthopedicprosthesis 330 can be used with other components described herein, suchas the subcutaneous port 14, the catheter 16, and the syringe 22. Inthis regard, the fluid passage 332 can be used to assist in diagnosing apotential infection around the tibial tray 34, such as by one of themethods described above. Similarly, the fluid passage 332 can be used todeliver antibiotics or other flowable material to an outer surface ofthe tibial tray.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the disclosure. Individual elements or featuresof a particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the disclosure, and all such modificationsare intended to be included within the scope of the disclosure.

What is claimed is:
 1. A drug delivery and diagnostic system comprising:an orthopedic implant having an outer attachment surface; a conduitcoupled to the outer attachment surface, the conduit having an inlet andat least one perforation formed thereon, the conduit adapted to passfluid between the inlet and the at least one perforation; and asubcutaneous port fluidly coupled to the inlet, wherein the subcutaneousport is adapted to communicate fluid through the inlet, along theconduit and out of the perforations around and along the outerattachment surface of the orthopedic implant.
 2. The drug delivery anddiagnostic system of claim 1, wherein the conduit is spirally wrappedaround the outer attachment surface.
 3. The drug delivery and diagnosticsystem of claim 2, wherein the conduit is formed of biocompatible metal.4. The drug delivery and diagnostic system of claim 3, wherein theconduit is one of welded, brazed or glued to the outer attachmentsurface.
 5. The drug delivery and diagnostic system of claim 1, whereinthe at least one perforation includes a plurality of perforations formedalong a length of the conduit.
 6. The drug delivery and diagnosticsystem of claim 1, wherein the orthopedic implant comprises a femoralhip stem having a groove formed there along, the groove formed on theouter attachment surface.
 7. The drug delivery and diagnostic system ofclaim 6, wherein the conduit nests in the groove.
 8. The drug deliveryand diagnostic system of claim 1, wherein the outer attachment surfaceincludes a groove formed in an outer surface of the orthopedic implant.9. The drug delivery and diagnostic system of claim 8, wherein theorthopedic implant is a femoral stem and the groove extends along a stemportion and a neck portion of the femoral stem.
 10. A drug delivery anddiagnostic system comprising: an orthopedic implant having an outerattachment surface; a conduit extending along the orthopedic implant andhaving an inlet and at least one outlet formed thereon, the conduitadapted to pass fluid between the inlet and the at least one outlet; anda subcutaneous port fluidly coupled to the inlet, wherein thesubcutaneous port is adapted to communicate fluid through the inlet,along the conduit, and through the at least one outlet.
 11. The drugdelivery and diagnostic system of claim 10, wherein the conduit iscoupled to the outer attachment surface.
 12. The drug delivery anddiagnostic system of claim 11, wherein the outer attachment surfaceincludes a groove formed therein.
 13. The drug delivery and diagnosticsystem of claim 10, wherein the at least one outlet includes at leastone perforation formed through the conduit.
 14. The drug delivery anddiagnostic system of claim 10, wherein the at least one outlet includesat least one substantially linear pipe that branches out and extendalong the outer attachment surface.
 15. The drug delivery and diagnosticsystem of claim 10, further comprising: a syringe to fluidly communicatewith the subcutaneous port.
 16. The drug delivery and diagnostic systemof claim 10, wherein the outer attachment surface extends around theorthopedic implant and the conduit is spirally wrapped around theorthopedic implant and coupled to the outer attachment surface.
 17. Adrug delivery and diagnostic system comprising: an orthopedic implanthaving an outer attachment surface comprising a groove formed in theouter attachment surface and extending around the orthopedic implant; aconduit extending along the orthopedic implant and having an inlet andat least one outlet formed thereon, the conduit adapted to pass fluidbetween the inlet and the at least one outlet; and a subcutaneous portfluidly coupled to the inlet, wherein the subcutaneous port is adaptedto communicate fluid through the inlet, along the conduit, and throughthe at least one outlet; wherein the conduit is coupled with the outerattachment surface.
 18. The drug delivery and diagnostic system of claim17, wherein the conduit is spirally wrapped around the orthopedicimplant and coupled within the groove.
 19. The drug delivery anddiagnostic system of claim 17, wherein the conduit is positioned in thegroove and the groove has a depth such that the conduit does not extendpast the outer attachment surface.
 20. The drug delivery and diagnosticsystem of claim 17, wherein the at least one outlet is selected from agroup comprising a perforation or a substantially linear pipe thatbranches out and extends along the outer attachment surface.
 21. Thedrug delivery and diagnostic system of claim 17, wherein the orthopedicimplant includes a femoral stem.
 22. The drug delivery and diagnosticsystem of claim 17, wherein the conduit and the subcutaneous port areconfigured to at least one of deliver a therapy or extract fluid.